I ended up exporting the tables from Sequel Pro using the "DROP TABLE IF EXISTS" syntax and then importing them (see screenshot).
If you don't use the DROP TABLE syntax (I believe this is the option in phpmyadmin) then just delete the tables before importing.
Basically, I spent a half an hour browsing the field_data_fieldname tables and others to see what sort of content they had and if they were pertinent to orders, line items, or users. I erred on the side of more db tables rather than less.
One of my field_data_fieldname fields was shared with other entity types, in addition to commerce_order, and so rather than clobber the incoming values, I had to create INSERT queries. Using Sequel Pro cut and paste did that for me. Make sure to get the field_revisions_fieldname table as well.
Make sure you empty out your cart before you import, else the cart will point to a possibly non-existent order and throw an entity metadata wrapper exception.
Here's the full list of tables:
`commerce_customer_profile`;
`commerce_customer_profile_revision`;
`commerce_line_item`;
`commerce_order`;
`commerce_order_revision`;
`commerce_payment_transaction`;
`commerce_payment_transaction_revision`;
`field_data_commerce_customer_address`;
`field_data_commerce_customer_billing`;
`field_data_commerce_customer_shipping`;
`field_data_commerce_line_items`;
`field_data_commerce_order_total`;
`field_data_commerce_shipping_service`;
`field_data_commerce_total`;
`field_data_commerce_unit_price`;
`field_data_message_commerce_body`;
`field_data_message_commerce_line_item`;
`field_data_message_commerce_order`;
`field_data_message_commerce_payment`;
`field_data_message_order_display_name`;
`field_data_message_text`;
`field_revision_commerce_customer_address`;
`field_revision_commerce_customer_billing`;
`field_revision_commerce_customer_shipping`;
`field_revision_commerce_shipping_service`;
`field_revision_commerce_total`;
`field_revision_commerce_unit_price`;
`field_revision_field_phone_number`;
`og_role`;
`og_role_permission`;
`og_users_roles`;
`users`;
`users_roles`;